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Application Note AN1001 ClearONE RC BGA Configuration Options

Differential Lines

Application Note AN1001 ClearONE RC BGA Configuration Options
Introduction
The double-sided construction of the CTS ceramic Ball Grid Array (BGA) package allows the PC board designer to closely locate passive resistor and capacitor elements near the active signal sources and loads. The BGA package solution, eases routing design, saving many hours of printed circuit layout time and space.
Description
ClearONE Resistor / Capacitor BGA (RC BGA) terminator networks provide a high performance passive termination. Designed on a ceramic substrate, RC BGA devices virtually eliminate channel capacitance while providing identical performance characteristics on each signal line. By choosing the RC BGA, the designer is provided with the opportunity to closely match signal line circuit performance. Each channel in the RC BGA will be closely matched in resistor and capacitor values with minimal channel capacitance and cross talk. Minimizing cross talk while closely matching channel performance is critical for differential signal line applications. Server back plane jitter filters and memory terminators can now have optimally placed bypass capacitors and fewer component placements.
Differential Lines
50 Backplane VTT 50 0.01uF
RC BGA
Figure 1. Back Plane Jitter Filter
Encapsulation Resistor System
Low VCR High Power Dissipation
Resistor Overglaze
Conductive Vias
Fully Filled
Ceramic Substrate
Ceramic Chip Capacitors Conductive Pads & Signal Lines
Signal Plane Ground Plane Printed Circuit Board Power Plane Signal Plane Solder Spheres
0.025" or 0.030" Dia. High Temperature 10 / 90 Sn / Pb Alloy
Solder Interface
63 / 37 Sn / Pb Eutectic
Traces
Figure 2. RC BGA Physical Construction
CTS Electronic Components Page 1 www.ctscorp.com ClearONE RC BGA Configuration Options
7 / 14 / 2005 AN1001
Component Specifications and Design Options
Resistors: Value Range Tolerance TCR Power Rating1 - Single Element - Total Package Capacitors: Values2 for X5R Dielectric: Values2 for X7R Dielectric: Values2 for COG Dielectric: Package: BGA Pitch Styles (Figure 3) Channel Capacitance Ball Grid Array Size
Notes: 1 2
Individual element and total device power requirements must both be considered for each application The Working Voltage must be considered when making the capacitor value and dielectric selections
Table 1. Resistor, Capacitor, and Package Options
Style J
Style K
Style L
Figure 3. RC BGA Styles
Environmental Performance
Operating Temperature Range: -55°C to +85°C
Standard Process Range with Epoxy Encapsulation
-55°C to +125°C (X7R & COG Dielectric) Range applies to a special order non-encapsulated version with
exposed capacitors.
CTS Electronic Components Page 2 www.ctscorp.com ClearONE RC BGA Configuration Options
7 / 14 / 2005 AN1001
Encapsulated RC BGA Figure 4. RC BGA Packages
Non-Encapsulated RC BGA
Conclusion
Referenced Documents
Application Notes:
Printed Circuit Assembly Guidelines RC BGA Rework AN-C1-PCAG-A AN-RC1-RW-A
http://www.ctscorp.com / components / clearone / appnotes.htm http://www.ctscorp.com / components / clearone.asp
LINK to Application Notes: Link to RC BGA Data Sheet:
Written by: Date:
Damon Niswonger 7 / 14 / 2005
CTS Electronic Components Page 3 www.ctscorp.com ClearONE RC BGA Configuration Options
7 / 14 / 2005 AN1001